Electrosurgical devices use electrical energy, most commonly radiofrequency (RF) energy, to cut tissue and/or cauterize blood vessels. During use, a voltage gradient is created at the tip of the device, thereby inducing current flow and related heat generation in the tissue. With sufficiently high levels of electrical energy, the heat generated is sufficient to cut the tissue and, advantageously, to cauterize severed blood vessels.
Current electrosurgical devices can cause the temperature of tissue being treated to rise significantly higher than 100° C., resulting in tissue desiccation, tissue sticking to the electrodes, tissue perforation, char formation and smoke generation. Peak tissue temperatures as a result of RF treatment of target tissue can be as high as 350° C., and such high temperatures may be transmitted to adjacent tissue via thermal diffusion. Undesirable results of such transmission to adjacent tissue include unintended thermal damage to the tissue.
One limitation of current electrosurgical devices arises from size constraints and dimensions. It is difficult to reach or gain access to some tissue and vessels due to anatomy and size constraints. Electrosurgical devices often have movable hinged scissors-like jaws at their tip that must open widely to be placed around the target tissue to be treated. Hinged jaws reduce visibility of the tip and often limit grasping capability of vessels due to force constraints. Further, devices currently used also often have long rigid shafts that cannot bend to maneuver around anatomical “tight” spots.
Laparoscopic or minimally-invasive surgery often involves multiple instrument passes through a trocar to achieve the desired tissue effect. Separate instruments are often required for coagulation and for cutting. Separate instruments may also be required to achieve surface hemostasis, such as when there is bleeding from the surface of an organ such as the liver. Multiple instrument passes are undesirable because they (1) waste valuable operating room time, (2) sometimes make it difficult to precisely relocate the target treatment site, (3) increase the risk of infection, and (4) increase the cost by increasing the number of different surgical instruments that are needed to complete the surgical procedure.
Accordingly, there is a need for a surgical device that reduces undesirable effects such as tissue desiccation and resulting tissue damage, char formation, smoke generation, and risk of infection, while at the same time providing improved accessibility to tissues and efficiency.